The present inventive concept relates to a semiconductor device. As demand for high performance, high speed, and/or multifunctionality in semiconductor devices has increased, the degree of integration of semiconductor devices has increased. When a semiconductor device having a fine pattern corresponding to a high integration trend of a semiconductor device is manufactured, it may be necessary to implement patterns having a fine width or a fine separation distance. Moreover, in order to overcome the limitation of element characteristics of a planar metal oxide semiconductor FET (MOSFET), a semiconductor device including a FinFET having a channel with a three-dimensional structure has been developed.